Diabetes is highly prevalent in the United States and is associated with increased morbidity from cardiovascular, renal, neurological and other complications. Our understanding of the pathogenesis of diabetes has benefited immensely from pharmacological, dietary and genetic manipulations in mice and other rodents. Despite the rapid increase in the use of gene targeting methodology to elucidate the molecular mechanisms mediating diabetes in mice, such efforts are often hampered by the absence of a clear phenotype. Failure to demonstrate a phenotype is attributable in part to the lack of expertise and/or facilities for evaluating physiologic and metabolic features in mice. We propose to establish a Mouse Phenotyping, Physiology and Metabolism Core, with the objective of providing investigators of the Penn Diabetes Center with state-of-the-art, timely and cost-effective diagnostic studies in mice. The core will offer services for analyzing glucose homeostasis, feeding behavior and energy balance, body composition, blood chemistry and hemodynamics. Activities of the core will be carried out by 2 technicians under the direction of Dr. Rex Ahima. The Phenotyping Core will maintain a databank of physiological, hormonal and metabolic measurements in mouse models of diabetes and obesity, and offer advice and training on various aspects of mouse physiology. Activities of the core will be coordinated with other core laboratories, Le Islet Cell Biology (Franz Matschinsky), Radioimmunoassay (Bryan Wolf), Transgenic and Chimeric (Nancy Cooke and Functional Genomics (Klaus Kaestner). These efforts will result in optimum data acquisition in diabetic mouse models, and facilitate the translation of ideas from the bench to mice and ultimately to humans.